You have mentioned that there is a contract between you and the boss that you will pay the am,ount in 6 months from Jan '11. You may be having a copy of the contract. It must have also been mentioned in your releiving letter OR they would have issued you a No Dues Certificate. Either of the ways, even a releiving letter is evidence enough that there are no dues pending unless it is mentioned as a conditional releiving letter. Your boss is trying to unnecessarily harass you. Lodge a police complaint immediately by stating all the facts. Please be sure to draft your own complaint and submit this at the local police station and get due acknowledgement on your application. May god bless you.